Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context: mail from the address resumes being heard, and the contact deleted by the block is NOT restored (routing the agent to restore_contact). That is meaningful side-effect disclosure beyond structured fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, front-loaded with the core action. The phrasing 'is heard again' is slightly figurative, but the total size is small and every sentence carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter toggle with annotations covering the safety profile and no output schema, the description is nearly complete. It covers the key side effect (contact remains deleted) that an agent would otherwise assume away.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Only one parameter with 100% schema description coverage, so the schema fully documents the 'email' field. The description adds no syntax or format detail beyond the schema baseline, so a 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Take an address off the blocked list.' It clearly identifies the inverse of block_a_sender without naming it explicitly. The second sentence distinguishes it from restore_contact by noting the deleted contact is not restored.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit guidance on when to use this versus list_blocked_senders or block_a_sender, nor any prerequisites (e.g., the sender must already be blocked). Usage is only implied by the phrase 'off the blocked list.'

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.